The role of exemplar typicality and encoding strategies in category retrieval-induced forgetting

Selective retrieval practice of category exemplars often impairs the recall of related items, a phenomenon known as retrieval-induced forgetting (RIF). In Experiment 1 the role of item typicality (high, low) and presentation format of category exemplars (random, grouped) were analysed, while in Experiment 2 two encoding strategies (inter and intracategory) to modulate RIF were tested. Exemplar typicality was the critical factor underlying RIF. Competition during retrieval practice rendered RIF in the typical exemplars, but RIF did not appear when the exemplars were low typicality. The greater impairment of strong exemplars is in line with the inhibitory account of RIF and the notion of interference dependence. Inhibition appeared with random and grouped presentations suggesting that presentation format of the exemplars is not a critical factor in modulating RIF in a category-cued recall task. Distinctive processing instructions using sentences that connected items from different categories (intercategory strategy) and integration instructions by using size to organise the exemplars within categories (intracategory strategy) easily avoided competition and the need of inhibition processes in recall.     

Memory bias for negative emotional words in recognition memory is driven by effects of category membership

Recognition memory studies often find that emotional items are more likely than neutral items to be labelled as studied. Previous work suggests this bias is driven by increased memory strength/familiarity for emotional items. We explored strength and bias interpretations of this effect with the conjecture that emotional stimuli might seem more familiar because they share features with studied items from the same category. Categorical effects were manipulated in a recognition task by presenting lists with a small, medium or large proportion of emotional words. The liberal memory bias for emotional words was only observed when a medium or large proportion of categorised words were presented in the lists. Similar, though weaker, effects were observed with categorised words that were not emotional (animal names). These results suggest that liberal memory bias for emotional items may be largely driven by effects of category membership.     

Cultural dimensions,socioeconomic development,climate, and emotional hedonic level

A research synthesis was conducted with four studies which correlated national mean self-ratings of affect balance (positive minus negative affect) and subjective well-being with the nations' cultural characteristics (individualism, masculinity, uncertainty avoidance, and power-distance national scores on Hofstede's dimensions), socioeconomic development (Human Development Index), and climate (absolute latitude). A meta-analysis of these collective level cross-cultural studies shows that individualism correlates positively with affect balance and subjective well-being, controlling for socioeconomic development, cultural femininity, power-distance, uncertainty avoidance, and climate. Similar results were found for individual-level data. The meaning of collective-level or national means of individual self-reports of affect balance is discussed.     

Aberrant neural mediation of verbal fluency in autism spectrum disorders

Objective

Contrasts of verbal fluency and automatic speech provide an opportunity to evaluate the neural underpinnings of generativity and flexibility in autism spectrum disorders (ASD).

Method

We used functional magnetic resonance imaging (fMRI) to contrast brain activity in high functioning ASD (n = 17, mean verbal IQ = 117) and neurotypical (NT; n = 20, mean verbal IQ = 112) adolescent and young adult males (12–23 years). Participants responded to three word generation conditions: automatic speech (reciting months), category fluency, and letter fluency.

Results

Our paradigm closely mirrored behavioral fluency tasks by requiring overt, free recall word generation while controlling for differences in verbal output between the groups and systematically increasing the task demand. The ASD group showed reduced neural response compared to the NT participants during fluency tasks in multiple regions of left anterior and posterior cortices, and sub-cortical structures. Six of these regions fell in cortico-striatal circuits previously linked to repetitive behaviors (Langen, Durston, Kas, van Engeland, & Staal, 2011), and activity in two of them (putamen and thalamus) was negatively correlated with autism repetitive behavior symptoms in the ASD group. In addition, response in left inferior frontal gyrus was differentially modulated in the ASD, relative to the NT, group as a function of task demand.

Conclusions

These data indicate a specific, atypical brain response in ASD to demanding generativity tasks that may have relevance to repetitive behavior symptoms in ASD as well as to difficulties generating original verbal responses.     

Diagnosis of cognitive impairment onset in older adults based on limitations in language skills / Diagnóstico del inicio del deterioro cognitivo en mayores a partir de limitaciones en las capacidades lingüísticas

Abstract

Progressive decline in language has been described in neuropsychological studies on Alzheimer’s disease and Mild Cognitive Impairment (MCI). We investigate this decline in its early stages, as well as its manifestations and the linguistic differences between participants at risk of developing MCI and without impairment. Participants were 36 older adults, all aged over 65. They were assessed using 31 subtests grouped into eight areas: fluency, comprehension, oral expression, reading, writing, memory, perceptual organization and processing speed. Our results showed significant differences between participants at risk of developing MCI and without impairment in verbal tests but not in manipulative tests. All participants at risk of developing MCI scored lowest in these eight areas. Our findings illustrate the relevance of investigating language skills in people at risk of developing MCI. Investigating these neuropsychological changes will help design appropriate intervention programmes that affect areas with higher levels of impairment.     

Constructing informative model priors using hierarchical methods

Despite their negative reputation, informative priors are very useful in inference. Priors that express psychologically meaningful intuitions damp out random fluctuations in the data due to sampling variability, without sacrificing flexibility. This article focuses on how an intuitively satisfying informative prior distribution can be constructed. In particular, it demonstrates how the hierarchical introduction of a parameterized generative account of the set of models under consideration naturally imposes a non-uniform prior distribution over the models, encoding existing intuitions about the models. The hierarchical approach for constructing informative model priors is made concrete using a worked example, the Varying Abstraction Model (VAM), a family of categorization models including and expanding the exemplar and prototype models. It is shown how psychological intuitions about the relative plausibilities of the models in the VAM can be formally captured in an informative prior distribution over these models, by specifying a theoretically informed process for generating the models in the VAM. The smoothing effect of the informative prior in estimation is demonstrated by considering ten previously published data sets from the category learning literature.     

Developmental differences in children's context-dependent word learning

In this study, 2.5-, 3-, and 4-year-olds (N = 108) participated in a novel noun generalization task in which background context was manipulated. During the learning phase of each trial, children were presented with exemplars in one or multiple background contexts. At the test, children were asked to generalize to a novel exemplar in either the same or a different context. The 2.5-year-olds’ performance was supported by matching contexts; otherwise, children in this age group demonstrated context dependent generalization. The 3-year-olds’ performance was also supported by matching contexts; however, children in this age group were aided by training in multiple contexts as well. Finally, the 4-year-olds demonstrated high performance in all conditions. The results are discussed in terms of the relationship between word learning and memory processes; both general memory development and memory developments specific to word learning (e.g., retention of linguistic labels) are likely to support word learning and generalization.     

Development of implicit and explicit category learning

We present two studies that examined developmental differences in the implicit and explicit acquisition of category knowledge. College-attending adults consistently outperformed school-age children on two separate information-integration paradigms due to children’s more frequent use of an explicit rule-based strategy. Accuracy rates were also higher for adults on a unidimensional rule-based task due to children’s more frequent use of the irrelevant dimension to guide their behavior. Results across these two studies suggest that the ability to learn categorization structures may be dependent on a child’s ability to inhibit output from the explicit system.     

汉语儿童英语口语发展及口语任务的影响作用

本研究选取小学二、四、六年级共96名学生,通过自我介绍、被试主动发问、看图说话和角色扮演四种任务对其英语口语产出的流利性、精确性和复杂性进行了测查,研究结果发现:(1)流利性在自我介绍、主动发问和看图说话任务上,年级发展趋势不显著,但是在角色扮演任务上,随着年级的增长,流利性随之增加;精确性的年级发展趋势不显著;复杂性随着年级的升高而升高;(2)小学儿童的口语流利性在四个任务上从高到低为角色扮演、主动发问、自我介绍和看图说话;在对话任务上的精确性显著高于独白任务的精确性,并且看图说话任务的精确性最低;英语口语的复杂性在自我介绍任务上最高,其次是主动发问,角色扮演与看图说话任务的口语复杂性最低。